I have created a BOM in a drawing based on an exiting BOM in an assembly. When I right-click on the BOM in the drawing and the corrosponding assembly, the option to "Split" the BOM does not appear in the pull-down menu. I have other drawings with BOMs based on their assembly BOM, and they work fine. Has anyone seen this before and have a solution to fix the problem? Corrupt file maybe?

Thanks for you help...